I have played more MMOs than I like to admit and Black Lion Trading Company is hands down the best auction house in gaming. As well as the rest of the game is made, the amount of thought that went into the auction house seems huge. I personaly think the combination of cross server AH and the ability to set your own purchase price is just what MMO economy needed for long term success. With the most sold and bought views, as well as sell history, there has never been a better AH for those who play it as a large portion of the game.
GW2 does some things right and some things wrong, but the auction house is revolutionary in depth and information. I really hope future games take notice, because this is how an AH is done right.
I'm surprised there isn't more attention to how awsome it is. I rarely start threads, but the AH is so good, I want to hear others input. Espeacialy if it's negative! Let me know the pitfalls I'm missing in my cloud of joy.